Graphite Recycling from Spent Lithium Ion Batteries

Rothermel S, Evertz M, Kasnatscheew J, Qi X, Grützke M, Winter M, Nowak S

Abstract

The present work reports on challenges in utilization of spent lithium-ion batteries(LIBs) - an increasingly important aspect associated with a significantly rising demandfor electric vehicles (EVs). In this context, the feasibility of anode recycling incombination with three different electrolyte extraction concepts is investigated. The firstmethod is based on a thermal treatment of graphite without electrolyte recovery. Thesecond method additionally utilizes a liquid carbon dioxide-assisted electrolyteextraction prior to thermal treatment. And the final investigated approach usessupercritical carbon dioxide as extractant, subsequently followed by the thermaltreatment. It is demonstrated that the best performance of recycled graphite anodes isshown when electrolyte extraction using liquid carbon dioxide is applied. Comparativestudies reveal that in the best case the electrochemical performance of recycledgraphite exceeds the benchmark consisting of a newly synthesized graphite anode. Asessential efforts towards electrolyte extraction and cathode recycling have been madein the past, the electrochemical behavior of recycled graphite demonstrating the bestperformance is investigated in combination with a recycled LiNi1/3Co1/3Mn1/3O2cathode.